The prevalence of obesity has grown to epidemic proportions and has been linked to severe health risks. In order for adequate treatments for obesity to be developed it must first be understood how obesity develops, what neural and physiological substrates are involved, and how external factors can influence it. The purpose of these studies is to use the diet-induced rat model of obesity to assess the neurological and physiological effects of exercise during the critical juvenile period of obesity development. Specifically, these studies will assess changes in food intake, body weight, and defense of body weight when juvenile rats are placed on a high fat diet and given free access to a running wheel and these aspects of energy homeostasis will be tracked through to adulthood. This model will mimic the onset of obesity in children who consume a high fat diet and participate in regular activity. In addition, these studies will focus on known neurological deficits in diet-induced rats and how exercise may serve to reverse these. The overall aim of these studies is to understand how exercise influences energy homeostasis and how exercise may serve to treat human obesity. [unreadable] [unreadable]